I have installed the BB Messenger and it works fine.
I must say that I have never seen an addon like this before. It really is amazing!
I would suggest that C.Birch continue to make it better than it is now and lets see how far this thing can fly.
Here are a few suggested addons:
1.Ability to add users to your buddylist directly from the messenger by their username.
2.The ability to accept or reject users wanting to be added to your buddylist.
3.The ability to block and remove users on your list.
4.Users' avatar displays when you are chatting with them one on one.
5.I have HiveMail installed on my site. Can I get a notification in BB Messenger when a new email arrives? 
6.I have V3Arcade installed in my forum. Can I challenge and play games with my buddys in BB Messenger?
7.Add a radio stream of your choice to BB Messenger.
8.Webcam and Audio.
9.Send files and photos.
10.Send links.
Really all I am suggesting are the typical features you would find in messengers like MSN and Yahoo. I am sure that if we put our minds together we can come up with new ideas that those guys never thought of.
If the BB Messenger got this far then why not?